Alongside other cards based on Mega Clefable and Mega Zygarde, this card will arrive as part of the set when it lands on March 27
As each are particularly located outside of where the reactor itself resides, they are each are marked with a corresponding Geoglyph
To give you a leg up, you can benefit from passive effects that multiply the amount of damage you inflict to the boss if you fulfill the conditions, and if a Raid Boss isn't defeated in 10 turns, it is passed down to other players so they can loan their assistance and chip in to defeat it
It also allows for fun Zombie synergy
Maybe one day WotC will invite planeswalkers as a Special Guest to a Magic event near you
Each of these cards is a "page" that, when put together with the other lore cards, will reveal an adventure and expand upon the story